An azimuthing propulsion unit is a configuration of marine propellers that can be rotated horizontally to any angle. This gives the ship better maneuverability than a fixed propeller and rudder system.
Typically a ship has two azimuthing propulsion units adjacent to each other. Each azimuthing propulsion unit may have a manual controller for controlling the propulsion unit.
In an emergency stopping situation, plurality of factors needs to be taken into account, such as the stopping distance, the stopping direction and safety of the stopping procedure for the ship equipment and the persons therein.
In a conventional emergency stopping procedure the propeller unit's orientation are maintained in the cruising position, that is, the propeller is pointing substantially towards the transom of the ship. The rotation direction of the propellers is, however, reversed. As the propellers are optimised for a pushing mode, the pulling mode of the reverse operation fails to stop the ship at an optimal distance.
A more efficient way of stopping the ship is a so called podway crash stop procedure, in which the propulsion units are rotated such that the propellers point at least substantially towards the head of the ship. Thereby the efficient pushing mode of the propellers may be utilized in stopping the ship.
However, the emergency stopping procedure is often carried out under high pressure and in confined space, it is very difficult and requires a lot of training and experience. Lacking such experience and confidence, the controller of the ship may be tempted to apply the conventional emergency stopping procedure and avoid using the more efficient but risky podway crash stop procedure.
An improved emergency stopping equipment and method is thus called for.